Kelsey Hayes rotors
I sold a set of SSBC brakes that came as a kit a while back, and it had those rotors on it. They are Mustang rotors for like 67-68 or along there. Take a look at the caliper mounting brackets. If they are a piece of flat plate bolted to the spindle, that may be an SSBC conversion kit. If so, there will be an adapter ring behind the seal on the backside of the rotors.
I sold a set of SSBC brakes that came as a kit a while back, and it had those rotors on it. They are Mustang rotors for like 67-68 or along there. Take a look at the caliper mounting brackets. If they are a piece of flat plate bolted to the spindle, that may be an SSBC conversion kit. If so, there will be an adapter ring behind the seal on the backside of the rotors.